1. Field of the Invention
The present invention relates to a control apparatus for a heater provided in a grip of a steering handle of a vehicle such as a motorcycle, a snowmobile, or a wet bike.
2. Related Background Art
Conventionally, there is an already known technology of providing a comfortable driving environment for a driver by providing a heater (an electric heater) in a grip (a part gripped by the driver) of a steering handle and controlling the electric energy supplied to the heater to warm the grip in a vehicle having an engine (including an internal combustion engine) as a propulsive source such as a motorcycle, a snowmobile, and a wet bike (for example, refer to Japanese Laid-Open Patent Publication No. 2004-67075 (hereinafter, referred to as patent document 1)).
In the grip heater control apparatus in this patent document 1, a switch unit is provided integrally with a controller for controlling the electric energy supplied to the heater in a cowling attached to the left side surface of the vehicle body. The switch unit is provided with an up switch and a down switch for increasing or decreasing a temperature of the heater with a driver's operation and four light emitting diodes for use in making a driver recognize the electrified condition of the heater by the number of lit light emitting diodes. Upon receiving operation outputs of the up switch and the down switch, the controller determines the number of lit light emitting diodes based on the number of ON times of the up switch and the number of ON times of the down switch. Then, the electricity to the heater is controlled by the PWM control on the basis of a duty factor to the heater (target electric energy to the heater) determined according to the number of lit light emitting diodes. Herewith, the controller supplies electricity to the corresponding number of light emitting diodes on the basis of the number of lit light emitting diodes, by which an electric current flows from the anode side of the light emitting diodes and thereby the light emitting diodes are turned on. At this point, the target electric energy to the heater specified by the operation of the up switch and the down switch can be visually identified by the number of lit light emitting diodes.
Meanwhile, a driver sometimes adjusts a temperature of the heater while checking the electrified condition of the heater during vehicle driving. Therefore, preferably the grip heater control apparatus enables the driver readily to control the temperature of the heater or to visually identify the electrified condition of the heater. Thereby, it is thought to be preferable to have a switch for controlling the temperature of the heater or an indicator for use in visually identifying the electrified condition of the heater in a place such as around a grip, for example. Around the grip, however, there is generally a need for installing required devices for the vehicle running such as a meter, a lamp switch, and the like, thus limiting the space for installing the switch or the indicator related to the grip heater control apparatus.
The grip heater control apparatus in the patent document 1 uses a plurality of light emitting diodes. Moreover, the switch unit is integral with the controller. Thereby, a wide space is needed to install the switch unit. Therefore, it is hard to install the switch unit in the limited space around the grip and thereby the switch unit has been mounted on the cowling attached to the left side surface of the vehicle in the grip heater control apparatus in the patent document 1.